| # x0 = # x1 + 1, ∃ z. x0 + z = x1 + a ' ⊦ x0 = x1 + a ' |
# x0 = # x1 + 1, x0 + z = x1 + a ', a ∈ z ⊦ z = []
Used simplifier rules: ni: ⊦ x + a ' = y + z ∧ ¬ a ∈ z → z = []; (forward) from specification list% ⊦ a ∈ x + y ↔ a ∈ x ∨ a ∈ y; (s)% ⊦ x = x + y ↔ y = []; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list%in-15: ⊦ x + a ' = y → a ∈ y; (forward) from specification list